Question: $-2\dfrac{1}{2} \div 3\dfrac{1}{2} = $
Solution: Let's start by converting the mixed numbers to fractions. $\phantom{=}-2\dfrac{1}{2} \div 3\dfrac{1}{2}$ $= -\dfrac{5}{2}\div\dfrac{7}{2}$ $= -\dfrac{5}{2}\cdot\dfrac{2}{7} ~~~~~~~\text{multiply by the reciprocal}$ $=-\dfrac{5}{{1}\cancel{2}}\cdot \dfrac{{1}\cancel{2}}{7}$ $=-\dfrac{5}{{1}}\cdot \dfrac{{1}}{7}$ $=-\dfrac{5}{7}$